When surgery is performed and wound closure is completed, there is an unmet need for an adhesive or sealant material that will seal the wound site and prevent fluid leakage in, for example a vessel anastomosis or lung resection. Generally, the key requirements of a tissue adhesive/sealant are:                (1) The surgical adhesive/sealant must have sufficient adhesive or cohesive strength to bond or seal the tissue repair site.        (2) Any exothermic process involved in the curing of the adhesive/sealant should not damage the surrounding tissue;        (3) The adhesive/sealant must not elicit any toxic response by the surrounding healthy tissue and should facilitate the re-growth of new tissue where possible;        (4) The adhesive/sealant should not liberate harmful degradation products;        (5) The adhesive/sealant should degrade, and as it does so, it should be replaced by new tissue with minimal scarring; and        (6) Any biodegradation products should not accumulate in the body but should be eliminated naturally either by excretion or        
Latent curing adhesive formulations comprising ketimines, electrophilic moieties and solvent are known in the field of surgical adhesives and sealants. For example, a latent curing adhesive may be the mixture of at least two components: one component bearing an electrophilic moiety, such as an isocyanate and nucleophile generating moiety, such as a ketimine. More specifically, the latent curing agent may be present in the two component mixture in a non-reactive form, i.e., latent form, during manufacture, storage and non-use, but may then be converted to a reactive curing agent upon application and use. As an example, the latent curing agent may be converted to a reactive curing agent in the presence of moisture that is present in the environment (e.g. wet tissue in the wound site, or supplied to the site upon use). It is well known in the art, for example, that a ketimine moiety may be used as a latent curing agent that can be converted to a reactive curing agent, i.e., an amine moiety, in the presence of water. After the ketimine moiety has been converted to its amine counterpart, the amine moiety may then react with the second component of the mixture, i.e., a reactive moiety such as an isocyanate, to form the desired cured adhesive and/or sealant. Examples of various ketimine based latent curing surgical adhesives that rely on solvent to be in liquid form under ambient conditions are described in published U.S. patent applications US2008/0039547 A1 and US2008/0039548 A1.
However, the latent curing adhesives described in the prior art are intended for use with the aid of a solvent, and are less ideal for human use as an internal surgical adhesive or sealant.